Anesthetic and respirator breathing devices commonly include a breathing circuit to direct gas flow to and away from the patient. The breathing circuit may include breathing circuit tubes, connectors and a patient interface. One category of breathing circuit tubes comprises dual lumen tubes. Dual lumen tubing refers generally to a single tubular apparatus with a partition separating the tube interior into two distinct lumens or channels. The two lumens may be implemented to separately accommodate a patient's inspiratory flow and expiratory flow within a single apparatus.
One problem with conventional dual lumen breathing circuit tubing is that condensation in the expiratory gas may accumulate in one of the lumen, and accumulated fluid can cause an occlusion.